Stretching along 36th Avenue in a pocket of Queens known as Little Brazil, Rio Market acts as an unofficial community center for Brazilians in New York: a Copacabana-style supermarket just off the N and W trains. This sort of home away from home for Brazilians is what Ricardo Bastos, 49, had in mind when he opened the place in 1994 as a tiny bodega. Over time, as more of his compatriots arrived, Mr. Bastos, who hails from Rio de Janeiro, moved his business across the street. “A lot of them come here just to speak Portuguese,” he said.